This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of the study is to test the role of SIBO in FD. The order of testing will be as follows: 1. Compare prevalence of abnormal lactulose breath test in patients with FD vs. healthy controls, 2. Compare the volume of tolerance to nutritive drink test in patients with FD vs. healthy controls, 3. Compare symptom score and ?stop volume? for a nutritive drink test in FD patients before vs. after antibiotic treatment in a randomized, double, blind, placebo-controlled study. We will use the best possible design of a randomized controlled trial rather than a randomized crossover trial, a cohort study or a case-control study to achieve the aim of eliminating as much as possible the effect of any confounding factor or bias. Specific Aim 1: We will determine the prevalence and association of SIBO and hypersensitivity in FD Specific Aim 2: We will determine the relationship between SIBO and hypersensitivity of FD using randomized antibiotic treatment. I D. Design (include things like whether the study is investigator initiated multi-center, pilot study, blinded, randomized, involves placebo, phase of study, prevention study): This is an investigator initiated pilot study to collect data for a subsequent NIH R01 application on Functional Dyspepsia. The project proposed involves a randomized, placebo-controlled, blinded design. If the central hypothesis is confirmed, a significant proposportion of patients presenting with functional dyspepsia should experience relief of symptoms within the study period.